A physician assistant may not:

1. (1) perform a medical act, task, or function which has not been listed and approved on the scope of practice guidelines;
2. (2) prescribe drugs, medications, or devices not specifically authorized by the supervising physician and documented in the written scope of practice guidelines;
3. (3) prescribe, under any circumstances, controlled substances in Schedule II;
4. (4) perform a medical act, task, or function that is outside the usual practice of the supervising physician.